he slammed republicans and the bush administration for the skyrocketing deficit. >> by the time the reins got turned over to barack and me, they had doubled the national debt in 8 years. >> reporter: with his path to the white house shrinking, florida's looking like a must-win for romney. but today, his runningmate, ckman paul ryan, focused on new hampshire, with four electoral votes. but ryan said that could be a difference in the race that will come to a handful of states. >> thank you, granite staters, for sending mitt romney to the white house and barack obama back to chicago. [cheering] >> reporter: the campaign shifts into a different stage this week, with wednesday night's high-stakes showed own showdown between about the barack obama and mitt romney. >> every change that has happened in a debate, if you look at the history, it's changed because of somebody's mannerisms or style -- they did badly or well. >> reporter: both candidates will spend the next few days in intense sessions. romney may have the most on the line. his campaign is looking that the for a chance for a game chang